Researchers found a link between ciradian rhythms and alcohol-induced hepatic steatosis, better known as fatty liver disease.
The condition is characterized by an "abnormal accumulation of fats in the cells of the liver," a University of Notre Dame news release reported. Fatty liver disease can interfere with the fat metabolism, it is almost always brough on by alcoholism or heavy drinking.
Fatty liver disease can lead to cirrhosis, which is a more serious alcohol-linked condition that includes scarring on the liver. Between 10 and 30 percent of heavy-drinkers develop alcoholic hepatitis.
A research team set out to discover "the molecular genetic basis for the molecular clock and liver steatosis," the news release reported.
The team used molecular biological approaches to make their findings. They fed mice alcohol over a long period of time, and were able to find a connection between alcohol-related liver steatosis and disturbances in the liver cells' 24-hour clock system.
This circadian clock is believed to be seperate from the "master" process that takes place in brain cells. Circadian clock regulate the body's behavior, especially in relation to the outside word such as day and night cycles. In the past disturbances in this cycle have been linked to mental disorders and metablic diseases.
"Liver function changes daily in a rhythmic manner and is coordinated with cycles of feeding-fasting and to the energy demands of the body, such as activity and rest," associate professor Giles Duffield, Notre Dame's Department of Biological Sciences and Eck Institute for Global Health, said. "These daily rhythms are regulated by the circadian clock within those liver cells, and disturbances to the molecular clock mechanism or poor temporal coordination of the clock with the timing of eating, or the sleep-wake and rest-activity cycle, can lead to illness."
The finding suggests the circadian clock either contributes to liver disease or development or steatosis interferes with the clock's natural process.
"Interestingly, the mechanism by which chronic alcohol intake is thought to alter the control of fat metabolism in the liver is also a shared signal to the circadian clock mechanism, this being the ratio of production of reduced nicotinamide adenine dinucleotide, or NADH, to NAD+. The authors suggest that this may be a key to the shared disturbance to the two biological mechanisms of lipid metabolism and the circadian clock," the news release reported.
